package ln.javatest.day05.Demo01;
public class Demo03Person {
    public static void main(String[] args) {
        Person person = new Person();
        person.show(); //我叫null，年龄0

        person.name = "王嘉尔";
        //person.age = 25;
        //person.age = -20
        // person.show();
        person.setAge(-20); //数据不合理！
        person.setAge(20);
        person.show(); //我叫王嘉尔，年龄20


    }
}
